Monitoring food and health news -- with particular attention to fads, fallacies and the "obesity" war

Summary of findings to date: Everything you can possibly eat or drink is both bad and good for you

"Let me have men about me that are fat... Yond Cassius has a lean and hungry look ... such men are dangerous." -- Shakespeare

Tuesday, December 04, 2012

Stupid salt scare finally becoming unglued

More counterproductive medical wisdom:"What we found was the people with the lowest sodium intake had the worst cardiovascular outcomes". I have been pointing to the stupidity of salt reduction since 2005 -- JR

The benefits of reduced sodium chloride consumption have long been accepted, but some experts say this should be taken with a grain of, well, salt. Mark Whittaker meets those shaking up accepted medical thought.

Any diabetic with high blood pressure who walks into George Jerums' Melbourne clinic will get the standard advice: if their salt intake is high, they should halve it. This is despite the fact that when Professor Jerums and his former PhD student, Dr Elif Ekinci, studied the salt intake of 638 elderly type-2 diabetics who went through his clinic at Heidelberg's Austin Health, they found that those who ate less salt were significantly more likely to die.

After 10 years, it emerged that for every extra 2.3 grams of sodium (equal to about a teaspoon of salt) in their urine over a day, their risk of dying fell by 28 per cent. Even though those who ate more salt tended to be fatter, fewer died from "all causes" and, contrary to what we've been told about the dangers of salt to the heart, fewer died from heart disease and stroke.

"If the person's blood pressure isn't controlled, it's an opportunity to say, 'Your salt intake is 200 [millimoles]. If you could halve it, that would help your blood pressure control'," says Jerums. "That's as far as we go. We don't say, 'But on the other hand, we don't really know what we're doing.'"

Surely, though, Jerums tells his patients to eat less salt because this study was just one flying in the face of decades of research proving that salt kills?

But it is not. It is one of many studies that have shown better results for diabetics, heart-attack sufferers, and people with high blood pressure who did not restrict their salt intake - the very people who get told to cut it most emphatically. About seven studies have linked increased salt intake to increased death rates, but there have been twice as many that have either found no link or that increased salt is associated with lower death rates.

Despite this, the consistent health message of recent decades has been that salt is bad.

When Ekinci and Jerums' research paper came out early last year, they were aware it challenged the salt-is-bad dogma but, in quick succession, four other studies followed with similar results.

The first was a study of 2807 Finns with type-1 diabetes. Those with both the lowest and highest sodium consumption died most often, while the majority in the middle were healthiest.

A study of 3681 Europeans with no history of cardiovascular disease found a death rate of 4.1 per cent in those with the lowest salt consumption, compared to 0.8 per cent in those with the highest salt consumption.

In November last year, a huge study of 28,800 Canadians found that those with the lowest salt intake died more often, as did those with the highest. The detrimental effects of a high-salt diet didn't kick in until their intake hit three to four times more salt than is currently recommended. However, those consuming the amount of salt recommended by health authorities were well within the low-sodium group that died more often and suffered more cardiovascular events.

But the most authoritative paper was by the independent non-profit Cochrane Collaboration, which specialises in analysing the known body of evidence on all manner of medical questions.

It looked at seven randomised controlled studies (RCTs) that had related salt intake to mortality with a total of 6200 people involved. It found "no strong evidence" linking salt to mortality or heart disease. This year, a separate Cochrane review of 163 studies said that reduced salt appeared to harm patients with bad hearts and both types of diabetes.

So why aren't the scientists rushing out to tell us of the latest research? Jerums and Ekinci tell me about six times between them that we can't read too much into observational studies like their own. "Observational studies are good for hypothesis building," says Ekinci, "but that's all." Even though they wrote in their paper that "such data calls into question universal recommendations that all adults should endeavour to reduce their salt intake", they won't say as much to me. "We don't want to create a war," Ekinci says.

One man they say they don't want to start a war with is Professor Bruce Neal from the Sydney head office of the George Institute for Global Health, a body that promotes public health programs around the world and which has taken the low-salt message global.

Neal says he got interested in salt because Australia spends about $1.5 billion a year treating hypertension (dangerously high blood pressure) "and we only effectively reach about 10 per cent of those with it". By spending $10 million to $20 million on a salt-reduction campaign, he says we'd save just as many lives for 1 to 2 per cent of the cost.

Neal admits there is no direct evidence that cutting salt saves lives. "You have to sort of infer it by saying, 'We reduce salt, we reduce blood pressure.' We know that reducing blood pressure reduces risk. There's a bit of direct evidence that is missing, but there's a mass of other evidence to support the notion that it would be effective."

This is the crux of the matter: too much salt raises blood pressure; raised blood pressure is a major risk factor for heart disease, stroke and kidney failure. Therefore, it is assumed that reducing salt will reduce those killer diseases.

That's been the hope since the 1970s and it is still assumed by the majority medical opinion, despite the studies that have said the opposite.

There is strong evidence that blood-pressure-lowering drugs save lives and, according to Neal, the only reason we can't say the same thing for salt reduction is there's no money in it. "No one will make $1 billion from marketing salt-reduced food," he says. "On the contrary, the food industry makes lots of money by adding salt to low-quality product that would otherwise be unpalatable."

But in October, Neal got $3.4 million from the federal government's National Health and Medical Research Council to conduct the biggest randomised controlled trial of salt consumption ever. His team will go to northern China and split 360 villages, so half receive normal salt and half receive their salt mixed with 30 per cent potassium chloride and 10 per cent magnesium to lower the total sodium chloride content. The 700,000 people in all those villages will be observed for death and illness over the following four years. [What a spupid research design! The deprived villagers will just make it up by getting salt from elsewhere]

"[The study] will provide a very low-cost intervention for these villages in rural China," Neal says. "But much more broadly than that, it will provide the evidence to really drive forward efforts to take salt out of food and try to reduce salt levels in Australia."

Yet some suggest that it would be ludicrous for a Western country to base its salt policy on a study of people in northern China, which has the highest salt consumption in the world and therefore, not surprisingly, counts strokes as its biggest killer. Among them is New York doctor Michael Alderman, who in the 1990s was among the first health professionals to suggest that the crystalline enemy might not be so bad after all.

The US was in the midst of a heart disease epidemic in the early 1970s when Alderman set up a program to go into workplaces, find out who had high blood pressure and treat it. "I, like everybody else, knew that lowering sodium intake of people with high blood pressure would be a good idea," he says. "So our program began with a low-sodium diet. We stopped that after realising the effect of asking people to go on a low-sodium diet was to have patients drop out of treatment. Nobody liked it. It was punishing the victim."

Over the years, Alderman became interested in why some people with high blood pressure had strokes and heart attacks, while the vast majority lived long lives. He worked with colleague John Laragh and concluded that renin (a hormone that regulates blood pressure by controlling sodium retention, fluid retention and artery width) was the key. "What we found was that the hypertensive people with the high-plasma renin were much more likely to have heart attacks and strokes than the same hypertensives who didn't have a high renin [level]," he says. The significance of this was that sodium and renin were inversely related: the folks who ate the least salt had the highest renin and hence a greater risk of heart attack and stroke.

"So," Alderman adds, "I looked in the literature because I believed like everybody else in the early '90s that a low-sodium diet was good for you, but what was the evidence? There was only one article in the world literature that related sodium intake to subsequent cardiovascular mortality. It was a paper published in 1985 from a study in Honolulu of Japanese immigrants and they reported no relationship between sodium intake and health outcomes. That was it. There was nothing else."

Alderman's 4000 patients had all had the sodium in their urine measured, so he compared that to their subsequent sickness and death. "What we found was the people with the lowest sodium intake had the worst cardiovascular outcomes.

"I knew this was going to fly in the face of conventional wisdom ... my own wisdom. At any rate, I submitted [a paper on the results] to The New England Journal of Medicine, and I got about a 10-page review written by some advocate of a low-sodium diet. No criticism of the method, the only criticism was they didn't like the results. It was rejected by three of the leading journals. I thought, 'Jesus, it's never going to get published.' "

The Journal of Hypertension eventually published the paper in 1995, along with an editorial saying it had to be wrong because of the "totality of the evidence" against salt. Alderman still riles at the words: "At that point there was only the one other paper and it showed no relationship. There was no 'totality of evidence'. It was baloney."

Alderman was invited to become a member of an advisory committee of a US industry body, the Salt Institute, and accepted $US750 to attend a meeting. "After that, I was always attacked as being a shill for the Salt Institute," he says. "I stayed on that committee for seven or eight years but never took any more money from them or had any support for my research from them or any commercial link, but my work was always dismissed on the basis that I was a crook. That only abated as more and more evidence appeared, culminating in those recent papers. But it doesn't seem to change policy. I find this so extraordinary."

Australia has a "suggested dietary target" of approximately four grams of salt a day: four-fifths of a teaspoon. But anyone consuming that much would be well inside the level at which many studies have shown people die more often.

When I ask Neal about Alderman's assertion that we should prove salt reduction is safe before we impose it on the population, he replies: "Alderman has made a career out of being a vocal sceptic. If you look at the totality of the evidence from all the different types of studies, it's a very clear picture ... humans evolved to live on a diet of less than a gram of sodium a day. They're not just getting a bit more than they actually need, they're getting 10 times more than they actually require. So it's not really a question of us taking away something that is normal and need to prove it safe; to the contrary, if we're going to pour salt into people at this level, we have to prove it is safe before we do it."

I didn't look at the totality of the evidence, but the Cochrane Collaboration did. It found salt reduction might be of benefit in northern China, but that "these results do not support that sodium reduction may have net beneficial effects in a population of Caucasians". And that "Reduced sodium intake seems to harm patients with heart insufficiency and diabetes type-1 and -2. In all three patient groups, reduced sodium intake is associated with increased mortality."

The Cochrane authors concluded: "After more than 150 RCTs and 13 population studies without an obvious signal in favour of sodium reduction, another position could be to accept that such a signal may not exist."

Michael Alderman can understand why Jerums and Ekinci are shy of starting a fight. "It hurt me to take the position I did," he says. "I happened to have some long-term research grants, but if I were a young investigator now trying to get grants, I would be very nervous."

Having said that, Alderman predicts the debate will be over by mid-decade and that salt's good reputation will be restored: "The evidence is so overwhelming. It's harder and harder for the zealots to say with each new paper there's something wrong with it ... It's not enough for them to say, 'I don't like your evidence.' They've got to have some evidence themselves."

HARDLY a day goes by without the media enlightening us with some ground-breaking new research to guide us along the rocky road of life.

A recent one that caught my eye was the output from Bristol and Oxford universities in Britain that the offspring of women who consumed ("as little as") two glasses of wine a week during pregnancy were (as much as) 1.8 IQ points less intelligent by the age of eight than peers whose mothers had abstained.

I can't help wondering how it is possible to prove that an eight-year-old would be (about) 1.8 per cent smarter if mummy hadn't been bingeing on two glasses of wine a week all those years ago.

Assuming this research is accurate and within any normal margin of error for IQ testing - which I would doubt - is it not possible that the drinking mothers are simply less intelligent than the non-drinking ones and genes are just doing what genes do? Are we to assume that mothers would respond honestly and without denial when questioned about their drinking habits while pregnant? Is it to be deduced that the more the mothers drank, the stupider the children became? Do the children of alcoholic mothers grow up to be research scientists? How much was Justin Bieber's mother drinking when he was in utero?

Today alcohol is good for us and tomorrow it's the devil's blood. Smoking rots your brain but can be beneficial if you want to concentrate for long periods or lose weight. There is good cholesterol and bad cholesterol, good fat and bad fat, good stress and bad stress. Some drugs are good for you, some drugs are bad for you (especially the illegal ones that don't attract GST). Exercise uplifts the mood unless the thought of the gym makes you depressed. Generally, sex is good for you but unprotected sex is bad unless you're married. If you're married, an affair can be good for the marriage or bad, depending on the context and whether or not you get found out. Mobile phones absolutely must cause cancer and we'll prove that if it kills us. And so on.

Why do I think that the people pumping out this stuff are funded based on the achievement of some sort of a result rather than its accuracy or relevance?

So, for all you pregnant women out there, may I suggest the following: keep knocking back the chardy and the strawberry daiquiris at mothers' group. You may be carrying the next Justin Bieber in there and it would be tragic if you deprived the world of that.

2 comments:

NSAIDS and BP.A recent report from Denmark (Circulation: Cardiovascular Quality and Outcomes, July 2010) involved reviewing the health records of more than 1 million people taking NSAID pain relievers such as ibuprofen (Advil, Motrin, etc.), diclofenac (Cataflam, Voltaren, etc.), celecoxib (Celebrex) and naproxen (Aleve, Naprosyn, etc.). The investigators found that, except for naproxen, "most NSAIDs are associated with increased cardiovascular mortality and morbidity."

Although you discovered that naproxen raises your blood pressure, this medicine is the only one in the study that did not increase the risk for heart attack or stroke. It is, however, associated with hypertension and gastrointestinal bleeding, so benefits and risks must be weighed carefully. http://articles.latimes.com/2010/jun/28/health/la-he-pharmacy-20100628

Potassium? I found out about my diabetes when a blood analysis lab wanted to repeat its testing because I had "elevated levels of Potassium, and with your diabetes" which indicates to me that potassium may be a problem.

Where it is not bunk is when it shows that some treatment or influence has no effect on lifespan or disease incidence. It is as convincing as disproof as it is unconvincing as proof. Think about it. As Einstein said: No amount of experimentation can ever prove me right; a single experiment can prove me wrong.

Epidemiological studies are useful for hypothesis-generating or for hypothesis-testing of theories already examined in experimental work but they do not enable causative inferences by themselves

The standard of reasoning that one commonly finds in epidemiological journal articles is akin to the following false syllogism:
Chairs have legs
You have legs
So therefore you are a chair

I am rather in despair that important medical research is plagued by arrant nonsense. The simple truth that correlation is not causation seems unknown to most medical writers. As a last ditch attempt to get that truth into a few more skulls let me be "offensive". Offensiveness may serve to get the matter noticed. So here is the story: There is about a -.5 correlation between lip size and IQ. Big lips predict low IQ. Your run-of-the mill medical researcher will pounce on that as a huge breakthrough in finding the causes of IQ -- and propound new theories about things such as blood circulation to explain how lips affect IQ. But that is nonsense. Big lips are mostly found on people of African ancestry and, as all the studies attest, Africans are a very low IQ group. The correlation arises because of heredity, not lip size. There is a third factor behind the correlation -- and the possibility of such third factors seems to be a jaw-dropping surprise to most medical researchers

SALT -- SALT -- SALT

1). A good example of an epidemiological disproof concerns the dreaded salt (NaCl). We are constantly told that we eat too much salt for good health and must cut back our consumption of it. Yet there is one nation that consumes huge amounts of salt. So do they all die young there? Quite the reverse: Japan has the world's highest concentration of centenarians. Taste Japan's favourite sauce -- soy sauce -- if you want to understand Japanese salt consumption. It's almost solid salt.

2). We need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. So the conventional wisdom is not only wrong. It is positively harmful

3). Table salt is a major source of iodine, which is why salt is normally "iodized" by official decree. Cutting back salt consumption runs the risk of iodine deficiency, with its huge adverse health impacts -- goiter, mental retardation etc. GIVE YOUR BABY PLENTY OF SALTY FOODS -- unless you want to turn it into a cretin

4). Our blood has roughly the same concentration of salt as sea-water so claims that the body cannot handle high levels of salt were always absurd

5). The latest academic study shows that LOW salt in your blood is most likely to lead to heart attacks. See JAMA. 2011;305(17):1777-1785. More here and here and here for similar findings. Salt is harmless but a deficiency of it is not. We need it. See also here

PEANUTS: There is a vaccination against peanut allergy -- peanuts themselves. Give peanut products (e.g. peanut butter -- or the original "Bamba" if you have Israeli contacts) to your baby as soon as it begins to take solid foods and that should immunize it for life. See here and here (scroll down). It's also likely that a mother who eats peanuts while she is lactating may confer some protection on her baby. See here

THE SIDE-EFFECT MANIA. If a drug is shown to have troublesome side-effects, there are always calls for it to be banned or not authorized for use in the first place. But that is insane. ALL drugs have side effects. Even aspirin causes stomach bleeding, for instance -- and paracetamol (acetaminophen) can wreck your liver. If a drug has no side effects, it will have no main effects either. If you want a side-effect-free drug, take a homeopathic remedy. They're just water.

Although I am an atheist, I have never wavered from my view that the New Testament is the best guide to living and I still enjoy reading it. Here is what the apostle Paul says about vegetarians: "For one believeth that he may eat all things: another, who is weak, eateth herbs. Let not him that eateth despise him that eateth not; and let not him which eateth not judge him that eateth." (Romans 14: 2.3). What perfect advice! That is real tolerance: Very different from the dogmatism of the food freaks. Interesting that vegetarianism is such an old compulsion, though.

Even if we concede that getting fat shortens your life, what right has anybody got to question someone's decision to accept that tradeoff for themselves? Such a decision could be just one version of the old idea that it is best to have a short life but a merry one. Even the Bible is supportive of that thinking. See Ecclesiastes 8:15 and Isaiah 22: 13. To deny the right to make such a personal decision is plainly Fascistic.

Obesity does NOT causes diabetes. But insatiable eating is a prominent symptom of diabetes. So diabetes DOES cause obesity, which accounts for the correlation between the two things. The streets are full of fatties who don't have diabetes. How come? If conventional medical theory were correct we should be in the midst of an epidemic of diabetes. A recent high quality study has also found that fatties are LESS likely to die of diabetes

Elite people frequently express disapproval of red meat eating as a way of expressing their felt superiority to the ordinary people who eat it

IQ: Political correctness makes IQ generally unmentionable so it is rarely controlled for in epidemiological studies. This is extremely regrettable as it tends to vitiate findings that do not control for it. When it is examined, it is routinely found to have pervasive effects. We read, for instance, that "The mother's IQ was more highly predictive of breastfeeding status than were her race, education, age, poverty status, smoking, the home environment, or the child's birth weight or birth order". So political correctness can render otherwise interesting findings moot

"To kill an error is as good a service as, and sometimes better than, the establishing of a new truth or fact" -- Charles Darwin

"Most men die of their remedies, not of their diseases", said Moliere. That may no longer be true in general but there is still a lot of false medical "wisdom" around that does harm to various degrees -- the statin and antioxidant fads, for instance. And showing its falsity is rarely the problem. The problem is getting people -- medical researchers in particular -- to abandon their preconceptions

Bertrand Russell could have been talking about today's conventional dietary "wisdom" when he said: "The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd; indeed in view of the silliness of the majority of mankind, a widespread belief is more likely to be foolish than sensible.”

The challenge, as John Maynard Keynes knew, "lies not so much in developing new ideas as in escaping from old ones".

"Obesity" is 77% genetic. So trying to make fatties slim is punishing them for the way they were born. That sort of thing is furiously condemned in relation to homosexuals so why is it OK for fatties?

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Some more problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize dietary fat. But Eskimos living on their traditional diet eat huge amounts of fat with no apparent ill-effects. At any given age they in fact have an exceptionally LOW incidence of cardiovascular disease. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

9). And how odd it is that we never hear of the huge American study which showed that women who eat lots of veggies have an INCREASED risk of stomach cancer? So the official recommendation to eat five lots of veggies every day might just be creating lots of cancer for the future! It's as plausible (i.e. not very) as all the other dietary "wisdom" we read about fat etc.

10). And will "this generation of Western children be the first in history to lead shorter lives than their parents did"? This is another anti-fat scare that emanates from a much-cited editorial in a prominent medical journal that said so. Yet this editorial offered no statistical basis for its opinion -- an opinion that flies directly in the face of the available evidence.

11). A major cause of increasing obesity is certainly the campaign against it -- as dieting usually makes people FATTER. If there were any sincerity to the obesity warriors, they would ban all diet advertising and otherwise shut up about it. Re-authorizing now-banned school playground activities and school outings would help too. But it is so much easier to blame obesity on the evil "multinationals" than it is to blame it on your own restrictions on the natural activities of kids

12. Fascism: "What we should be doing is monitoring children from birth so we can detect any deviations from the norm at an early stage and action can be taken". Who said that? Joe Stalin? Adolf Hitler? Orwell's "Big Brother"? The Spanish Inquisition? Generalissimo Francisco Franco Bahamonde? None of those. It was Dr Colin Waine, chairman of Britain's National Obesity Forum. What a fine fellow!

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Trans fats: For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.

The "antioxidant" religion: The experimental evidence is that antioxidants SHORTEN your life, if anything. Studies here and here and here and here and here and here and here and here, for instance. That they are of benefit is a great theory but it is one that has been coshed by reality plenty of times.

The medical consensus is often wrong. The best known wrongheaded medical orthodoxy is that stomach ulcers could not be caused by bacteria because the stomach is so acidic. Disproof of that view first appeared in 1875 (Yes. 1875) but the falsity of the view was not widely recognized until 1990. Only heroic efforts finally overturned the consensus and led to a cure for stomach ulcers. See
here and here and here.

Dieticians are just modern-day witch-doctors. There is no undergirding in double-blind studies for their usual recommendations

The fragility of current medical wisdom: Would you believe that even Old Testament wisdom can sometimes trump medical wisdom? Note this quote: "Spiess discussed Swedish research on cardiac patients that compared Jehovah's Witnesses who refused blood transfusions to patients with similar disease progression during open-heart surgery. The research found those who refused transfusions had noticeably better survival rates.

Medical wisdom can in fact fly in the face of the known facts. How often do we hear reverent praise for the Mediterranean diet? Yet both Australians and Japanese live longer than Greeks and Italians, despite having very different diets. The traditional Australian diet is in fact about as opposite to the Mediterranean diet as you can get. The reverence for the Mediterranean diet can only be understood therefore as some sort of Anglo-Saxon cultural cringe. It is quite brainless. Why are not the Australian and Japanese diets extolled if health is the matter at issue?

Since many of my posts here make severe criticisms of medical research, I should perhaps point out that I am also a severe critic of much research in my own field of psychology. See here and here

This is NOT an "alternative medicine" site. Perhaps the only (weak) excuse for the poorly substantiated claims that often appear in the medical literature is the even poorer level of substantiation offered in the "alternative" literature.

I used to teach social statistics in a major Australian university and I find medical statistics pretty obfuscatory. They seem uniformly designed to make mountains out of molehills. Many times in the academic literature I have excoriated my colleagues in psychology and sociology for going ga-ga over very weak correlations but what I find in the medical literature makes the findings in the social sciences look positively muscular. In fact, medical findings are almost never reported as correlations -- because to do so would exhibit how laughably trivial they generally are. If (say) 3 individuals in a thousand in a control group had some sort of an adverse outcome versus 4 out of a thousand in a group undergoing some treatment, the difference will be published in the medical literature with great excitement and intimations of its importance. In fact, of course, such small differences are almost certainly random noise and are in any rational calculus unimportant. And statistical significance is little help in determining the importance of a finding. Statistical significance simply tells you that the result was unlikely to be an effect of small sample size. But a statistically significant difference could have been due to any number of other randomly-present factors.

"The modern literature on hate crimes began with a remarkable 1933 book by Arthur Raper titled The Tragedy of Lynching. Raper assembled data on the number of lynchings each year in the South and on the price of an acre's yield of cotton. He calculated the correlation coefficient between the two series at -0.532. In other words, when the economy was doing well, the number of lynchings was lower.... In 2001, Donald Green, Laurence McFalls, and Jennifer Smith published a paper that demolished the alleged connection between economic conditions and lynchings in Raper's data. Raper had the misfortune of stopping his analysis in 1929. After the Great Depression hit, the price of cotton plummeted and economic conditions deteriorated, yet lynchings continued to fall. The correlation disappeared altogether when more years of data were added."

So we must be sure to base our conclusions on ALL the data. But in medical research, data selectivity and the "overlooking" of discordant research findings is epidemic.

The Truth About Ancel Keys. Keys was a brilliant man but his concentration on heart disease misled him. He was right that high fat intake predicted high rates of heart disease (though it was ANIMAL fat in particular that was the "culprit") but he overlooked that the same intake predicted LESS mortality from other causes. The same narrow vision led him to be the earliest prominent advocate of the "Mediterranean diet" hypothesis. It's true that Mediterraneans have less heart disease but they have more of other causes of death, so that Mediterranean countries do not have particularly long lifespans when compared with other developed countries. If there are any lessons about diet to be learned from lifespans, it is un-Mediterranean countries like Australia and the Nordic countries that one should look to.

The intellectual Roman Emperor Marcus Aurelius (AD 121-180) could have been speaking of the prevailing health "wisdom" of today when he said: "The object in life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane."

Improbable events do happen at random -- as mathematician John Brignell notes rather tartly: "Consider, instead, my experiences in the village pub swindle. It is based on the weekly bonus ball in the National Lottery. It so happens that my birth date is 13, so that is the number I always choose. With a few occasional absences abroad I have paid my pound every week for a year and a half, but have never won. Some of my neighbours win frequently; one in three consecutive weeks. Furthermore, I always put in a pound for my wife for her birth date, which is 11. She has never won either. The probability of neither of these numbers coming up in that period is less than 5%, which for an epidemiologist is significant enough to publish a paper.

Kids are not shy anymore. They are "autistic". Autism is a real problem but the rise in its incidence seems likely to be the product of overdiagnosis -- the now common tendency to medicalize almost all problems.

One of the great pleasures in life is the first mouthful of cold beer on a hot day -- and the food Puritans can stick that wherever they like

NOTE: The archives provided by blogspot below are rather inconvenient. They break each month up into small bits. If you want to scan whole months at a time, the backup archives will suit better. See here or here